middle mouse key alternative
You can emulate 3 Button Mouse.
Blender 2.7
File &gt; User Preferences... (Cmd + ,)
Blender &gt;= 2.8
Edit &gt; Preferences...
In the Input tab, check &quot;Emulate 3 Button Mouse&quot;.
Now, you can emulate the middle button by pressing Alt + LMB (Left Mouse Button).